The 640GB StoreJet 25M3 Ext. Hard Drive with USB 3.0 Express Card Adapter is a B&H Kit that bundles an ExpressCard/34 USB 3.0 adapter for your Windows laptop together with a 640GB external hard drive. The portable hard drive features USB 3.0 connectivity, providing data transfer speeds up to 5Gbps, over ten times faster than those of USB 2.0. The adapter includes two USB 3.0 ports and fits in a free ExpressCard/34 slot on your Windows laptop. If you wanted USB 3.0 speeds with vast external storage to boot for your laptop, then look no further.